Bi 4: Cho biu thc: A=(1x−x−1−x−3x−1−2)(22−x−x+22x−x) a, Rt gn A. b, Tnh A khi x=3−22 sans-serif cap B sans-serif i space 4 : space sans-serif cap C sans-serif h sans-serif o space sans-serif b sans-serif i sans-serif u space sans-serif t sans-serif h sans-serif c : space cap A equals open paren the fraction with numerator 1 and denominator the square root of x end root minus the square root of x minus 1 end root end fraction minus the fraction with numerator x minus 3 and denominator the square root of x minus 1 end root minus the square root of 2 end root end fraction close paren open paren the fraction with numerator 2 and denominator the square root of 2 end root minus the square root of x end root end fraction minus the fraction with numerator the square root of x end root plus the square root of 2 end root and denominator the square root of 2 x end root minus x end fraction close paren space sans-serif a comma space sans-serif cap R sans-serif t space sans-serif g sans-serif n space sans-serif cap A point space sans-serif b comma space sans-serif cap T sans-serif n sans-serif h space sans-serif cap A space sans-serif k sans-serif h sans-serif i space x equals 3 minus 2 the square root of 2 end root spaceBài 4: Cho biểu thức: A = (1/(sqrt(x) - sqrt(x - 1)) - (x - 3)/(sqrt(x - 1) - sqrt(2)))(2/(sqrt(2) - sqrt(x)) - (sqrt(x) + sqrt(2))/(sqrt(2x) - x)) a, Rút gọn A. b, Tính A khi x = 3 - 2sqrt(2)
